Lens’ Juma Bah suffered a serious injury during training on Saturday morning when he collided head-to-head with teammate Jonathan Gradit, Lequipe reports.

As a result, Bah lost two teeth and spent the afternoon in the hospital for further examination. He will miss the Lille derby this Sunday at 8:45 p.m. and will not return to action until Tuesday, by concussion protocol.

Bah sat in shock for several minutes following the collision and will likely be replaced by Malang Sarr at kickoff. Meanwhile, Gradit has also sustained an injury, requiring stitches for a cut on his eyebrow. His fitness is currently uncertain, and a medical examination will assess the condition of his swollen eye on Sunday morning after he wakes up.

With both players’ statuses in question, Lens is expected to play in a 5-3-2 formation if Gradit is fit. If he cannot play, coach Will Still may need to switch to a 4-5-1 formation.

Two teams competing for European football next season face off in Ligue 1 this weekend as Lille hosts Lens in the Derby du Nord on Sunday evening.